A Pooled Analysis of Limited-Stage Small-Cell Lung Cancer Patients Treated with Induction Chemotherapy Followed by Concurrent Platinum-Based Chemotherapy and 70 Gy Daily Radiotherapy: CALGB 30904

Introduction:Standard therapy for limited-stage small-cell lung cancer (L-SCLC) is concurrent chemotherapy and radiotherapy (RT) followed by prophylactic cranial radiotherapy. Although many consider the standard RT regimen to be 45 Gy in 1.5 Gy twice-daily fractions, this has failed to gain widespread acceptance. We pooled data of patients assigned to receive daily RT of 70 Gy from three, consecutive prospective Cancer and Leukemia Group B L-SCLC cancer trials and report the results here.Methods:All patients from consecutive Cancer and Leukemia Group B L-SCLC trials (39808, 30002, and 30206) using high-dosage daily RT with concurrent chemotherapy were included, and analyzed for toxicity, disease control, and survival. Overall survival (OS) and progression-free survival (PFS) were modeled using Cox proportional hazards models. Prognostic variables for OS-rate and PFS-rate were assessed using logistic regression model.Results:Two hundred patients were included. The median follow-up was 78 months. Grade 3 or greater esophagitis was 23%. The median OS for pooled population was 19.9 months (95% confidence interval [CI]: 16.7–22.3), and 5-year OS rate was 20% (95% CI: 16–27%). The 2-year PFS was 26% (95% CI: 21–32%). Multivariate analysis found younger age (p = 0.02; hazard ratio [HR]: 1.023; 95% CI: 21-32), and female sex (p = 0.02; HR:0.69; 95% CI: 0.50-0.94) independently associated with improved overall survival.Conclusion:Two-Gy daily RT to a total dosage of 70 Gy was well tolerated with similar survival to 45 Gy (1.5 Gy twice-daily). This experience may aid practitioners decide whether high-dosage daily RT with platinum-based chemotherapy is appropriate outside of a clinical trial